Transmission-type electronic pen

ABSTRACT

A transmission-type electronic pen that detects a hover state by a position detecting device and achieves power savings is provided. The pen includes a transmission circuit that transmits a signal to a position detecting device and a detector configured to detect a direct act of a user. The pen includes a pressure detector configured to detect whether a pressure is applied to a tip of a core body, and a controller configured to activate and control transmission operation of the transmission circuit based on detection outputs of the detector and the pressure detector. The transmission circuit is controlled in accordance with any of a plurality of transmission operation states including at least a power saving state. When detecting an act of the user, the controller activates and sets the transmission circuit to a first transmission operation state of the plurality of states.

BACKGROUND Technical Field

This application is directed to a transmission-type electronic pen usedwith a position detecting device.

Description of Related Art

Position input devices are composed of a position indicator and aposition detecting device that detects a position indicated by theposition indicator are known. As one of such position input devices,there is a position input device receiving a signal transmitted from apen-type position indicator by a position detecting device and therebydetecting a position indicated by the position indicator. Specifically,the position indicator used in this kind of position input device isarranged with a configuration of a transmission-type electronic pen thatincludes a power supply circuit and includes a transmission circuit thattransmits a signal from the transmission circuit to the positiondetecting device (for example, refer to Patent Document 1 (JapanesePatent Publication No. 1995-295722) and Patent Document 2 (JapanesePatent Publication No. 2007-164356)).

As the power supply circuit of this kind of transmission-type electronicpen, an internal power supply circuit including a primary battery and apower supply circuit of a secondary battery charge system has beenproposed. However, draining of the battery due to continuous signaltransmission is a problem. Specifically, power consumption due tocontinuous signal transmission is high and, therefore, it is necessaryto frequently replace the battery or frequently charge the battery,which is troublesome. Therefore, in this kind of transmission-typeelectronic pen, a high-density battery has come to be used and ahigh-capacity double-layer capacitor has come to be used as in PatentDocument 2. However, there is a limit also to increasing the batterycapacity.

In order to avoid this problem, in this kind of transmission-typeelectronic pen, there is an electronic pen that is configured such thatthe transmission circuit starts transmission operation through pressingof a side switch or a knock switch arranged on a shaft (tail part).However, in order to carry out an input operation of a positionindication by the transmission-type electronic pen, the switch needs tobe pressed, which is troublesome. In addition, there is a problem inthat if turning off the switch is forgotten, the transmission circuitkeeps on carrying out the transmission operation and the power isuselessly consumed.

Therefore, in this kind of conventional transmission-type electronicpen, there has also been arranged an electronic pen that is configuredsuch that a pressure sensing switch that is turned on by a pressureapplied to a core body whose tip serving as a pen tip protrudes to theoutside is arranged in a casing and a transmission circuit startstransmission operation by detecting that this pressure sensing switch isturned on.

PRIOR ART DOCUMENTS Patent Documents

Patent Document 1: Japanese Patent Publication No. 1995-295722

Patent Document 2: Japanese Patent Publication No. 2007-164356

BRIEF SUMMARY Technical Problems

However, in the transmission-type electronic pen using the pressuresensing switch, action of pressing the pen tip to turn on the pressuresensing switch is necessary. In normal cases, a user presses the pen tipof this kind of transmission-type electronic pen against an inputsurface of a position detecting device or the vicinity of the inputsurface to turn on the pressure sensing switch and start transmission,and thereafter carries out position indication operation in the positiondetecting device.

Therefore, the transmission circuit of this transmission-type electronicpen does not carry out the transmission operation until the pen tip ispressed against the input surface of the position detecting device toturn on the pressure sensing switch, for example. For this reason, it isimpossible to carry out detection of the presence of thetransmission-type electronic pen over the position detecting device,i.e., detection of a so-called hover state. As a result, time lag iscaused although a user starts operation of position indication by thetransmission-type electronic pen on the input surface of the positiondetecting device. Thus, the user is confounded for a moment and a senseof discomfort is caused. This is a significant problem for an electronicpen aimed at offering usability similar to that of paper and a pencil.

Furthermore, in the transmission-type electronic pen, using the pressuresensing switch, after the pressure sensing switch is turned on once,even when the transmission-type electronic pen is separated from thesensor surface of the position detecting device and the pressure sensingswitch is turned off, the transmission operation of the transmissioncircuit is continued until a predetermined time elapses from the turningoff of the pressure sensing switch. The purpose of this is to allow theuser to immediately carry out the next indication input operationwithout turning on the pressure sensing switch again when the time ofthe separation of the transmission-type electronic pen from the inputsurface of the position detecting device is a short time.

However, the state after the pressure sensing switch is turned off isnot only the case in which the user immediately carries out indicationinput operation again by the electronic pen but also the state in whichthe user releases the electronic pen from the hand and does notimmediately carry out indication input operation again. Conventionally,it is impossible to discriminate between the two and, even when thepressure sensing switch is turned off, always the electronic pencontinues the transmission operation of the transmission circuit for thepredetermined time and uselessly consumes the power in some cases.

In view of the above problems, the embodiment described herein provide atransmission-type electronic pen that can allow detection of the hoverstate by a position detecting device to be always possible even at thestart of use and can achieve power savings.

Technical Solution

In order to solve the above-described problems, a transmission-typeelectronic pen used with a position detecting device is provided inaccordance with an embodiment, where the transmission-type electronicpen includes:

a tubular casing,

a core body arranged in the casing such that a tip thereof protrudes toexternally extend from one opening of the casing,

a supply source of a source voltage provided in the casing,

a transmission circuit that transmits a signal supplied to the positiondetecting device,

a detector configured to detect a direct act of a user to the casing,serving as a trigger for start of use of the transmission-typeelectronic pen,

a pressure detector configured to detect whether a pressure is beingapplied to the tip of the core body, and

a controller configured to control transmission operation of thetransmission circuit based on a detection output of the detector and adetection output from the pressure detector,

wherein activation control of the transmission circuit is carried out bythe controller, and the transmission circuit is controlled to any of aplurality of kinds of transmission operation states including at least atransmission operation state of power saving when being activated, and

when detecting an act of the user by the detector, the controlleractivates the transmission circuit and carries out control to cause thetransmission circuit to carry out transmission operation in a firsttransmission operation state that is any of the plurality of kinds oftransmission operation states.

In an embodiment, when a user makes a direct act to the casing throughbringing a hand into contact with the casing for holding the casing withthe hand or holding the casing with a hand and raising the casing inorder to start use of the transmission-type electronic pen, the directact is detected by the detector.

The controller receives a detection output of the direct act of the userto the casing from this detector and activates the transmission circuitto carry out control to cause the transmission circuit to become thefirst transmission operation state that is any of the plurality of kindsof transmission operation states and start transmission of a signal.

In this manner, the transmission-type electronic pen becomes in thestate in which the transmission circuit transmits the signal throughonly a direct act to the casing serving as a trigger for the start ofuse of the transmission-type electronic pen by a user. Thus, the hoverstate over the input surface of the sensor of the position detectingdevice can be detected.

Furthermore, when the user causes the transmission-type electronic pento touch the input surface of the sensor of the position detectingdevice, the touch is detected by the pressure detector and the pressuredetection output is supplied to the controller. The controller controlsthe transmission operation state of the transmission circuit to achievefurther power saving based on the detection output of the direct act ofthe user to the casing from the detector and the detection output in thepressure detector.

For example, the controller sets the first transmission operation stateas a transmission operation state that is a power saving state butallows detection of the hover state. Thereafter, when thetransmission-type electronic pen is caused to touch e.g., the inputsurface of the sensor of the position detecting device by a user and thetouch is detected by the pressure detector, the controller carries outcontrol to set the normal operation state from the power saving state tofacilitate detection of the position indicated by the transmission-typeelectronic pen in the position detecting device. Furthermore, when it isdetected that the touch with the input surface of the position detectingdevice by the transmission-type electronic pen is released by thepressure detector in the state in which it is detected that the user iscontinuing the direct act to the casing serving as a trigger for thestart of use of the transmission-type electronic pen based on thedetection output of the detector, the controller returns thetransmission operation state of the transmission circuit to thetransmission operation state of power saving to avoid useless powerconsumption.

Advantageous Effects

According to the transmission-type electronic pen in accordance with anembodiment, the transmission circuit is activated to be set to the firsttransmission operation state when a direct act of a user to the casing,serving as a trigger for the start of use of the transmission-typeelectronic pen, is detected by the detector. Thus, detection of thehover state by the position detecting device can be allowed to be alwayspossible, including when use of the transmission-type electronic pen isstarted.

Furthermore, in the transmission-type electronic pen, the controller isconfigured to control the transmission operation of the transmissioncircuit to any of the plurality of kinds of transmission operationstates including at least the transmission operation state of powersaving based on the detection output of the detector that detects adirect act of a user to the casing serving as a trigger for the start ofuse of the transmission-type electronic pen and the detection outputfrom the pressure detector that detects whether a pressure is beingapplied to the tip of the core body based on the motion of the core bodydue to the pressure applied to the tip. Thus, further power saving canbe achieved.

BRIEF DESCRIPTION OF SEVERAL VIEWS OF THE DRAWINGS

FIG. 1 is a diagram showing a first embodiment of a transmission-typeelectronic pen with electronic equipment including a position detectingdevice.

FIG. 2 is a block diagram showing a configuration example of a penindication detecting circuit of the position detecting device used withthe first embodiment of the transmission-type electronic pen.

FIGS. 3A-3C are diagrams showing a transmission signal of the firstembodiment of the transmission-type electronic pen.

FIGS. 4A and 4B are diagrams showing a mechanical configuration exampleof the first embodiment of the transmission-type electronic pen.

FIG. 5 shows an example configuration of an electronic circuit of thefirst embodiment of the transmission-type electronic pen.

FIG. 6 is a diagram showing transition of a transmission operation statein power saving control in the first embodiment of the transmission-typeelectronic pen.

FIG. 7 is a diagram showing part of a flow diagram of operation of thepower saving control in the first embodiment of the transmission-typeelectronic pen.

FIG. 8 is a diagram showing part of the flow diagram of the operation ofthe power saving control in the first embodiment of thetransmission-type electronic pen.

FIG. 9 is a diagram showing part of the flow diagram of the operation ofthe power saving control in the first embodiment of thetransmission-type electronic pen.

FIG. 10 shows an example configuration of an electronic circuit of asecond embodiment of the transmission-type electronic pen.

FIG. 11 is a diagram showing transition of a transmission operationstate in power saving control in a third embodiment of thetransmission-type electronic pen.

FIGS. 12A and 12B are high level diagrams of an example configuration ofanother embodiment of the transmission-type electronic pen.

FIGS. 13A-13C are high level diagrams of an example configuration ofanother embodiment of the transmission-type electronic pen.

FIG. 14 is a diagram of an example configuration of another embodimentof the transmission-type electronic pen.

DETAILED DESCRIPTION

Several embodiments of the transmission-type electronic pen will bedescribed below with reference to the drawings.

First Embodiment

An embodiment of the transmission-type electronic pen according to thisdisclosure will be described below with reference to drawings. FIG. 1 toFIG. 5 are diagrams of a configuration example of a transmission-typeelectronic pen 1 in accordance with an embodiment. The transmission-typeelectronic pen 1 of this embodiment is used with electronic equipmentincluding a position detecting device of a capacitive system.

FIG. 1 is a diagram showing one example of a tablet-type informationterminal 200 as an example of electronic equipment used with thetransmission-type electronic pen 1 according to an embodiment. In thisexample, the tablet-type information terminal 200 includes a displayscreen 200D of a display device, such as an LCD (Liquid CrystalDisplay), and includes a position detecting device 201 of a capacitivesystem, in this example, at the upper part (front surface side) of thedisplay screen 200D.

[Configuration Example of Position Detecting Device 201]

As shown in FIG. 2, the position detecting device 201 of this embodimentis composed of a sensor 202 that forms this position detecting device201 and a pen indication detecting circuit 203 connected to this sensor202.

In this example, the sensor 202 is a component formed by stacking afirst conductor group 211, an insulating layer (diagrammaticrepresentation not shown), and a second conductor group 212 sequentiallyfrom the lower layer side (a sectional view is not shown). For example,the first conductor group 211 is a group obtained by disposing pluralfirst conductors 211Y₁, 211Y₂, . . . , and 211Y_(m) (m is an integerequal to or larger than 1) that extend along the horizontal direction(X-axis direction) in the Y-axis direction in parallel, with the pluralfirst conductors 211Y₁, 211Y₂, . . . , and 211Y_(m) separated from eachother by predetermined intervals.

Furthermore, the second conductor group 212 is a group obtained bydisposing plural second conductors 212X₁, 212X₂, . . . , and 212X_(n) (nis an integer equal to or larger than 1) that extend along a directionintersecting the extension direction of the first conductors 211Y₁,211Y₂, . . . , and 211Y_(m), specifically the vertical direction (Y-axisdirection) orthogonal to the extension direction, in this example, inthe X-axis direction in parallel, with the plural second conductors212X₁, 212X₂, . . . , and 212X_(n) separated from each other bypredetermined intervals.

As above, the sensor 202 of the position detecting device 201 isconfigured to detect a position indicated by an indicating body, such asthe transmission-type electronic pen 1, using the sensor pattern formedthe first conductor group 211 intersecting the second conductor group212.

In the following description, regarding the first conductors 211Y₁,211Y₂, . . . , and 211Y_(m), the conductor will be referred to as thefirst conductor 211Y when there is no need to distinguish between therespective conductors. Similarly, regarding the second conductors 212X₁,212X₂, . . . , and 212X_(n), the conductor will be referred to as thesecond conductor 212X when there is no need to distinguish between therespective conductors.

In the position detecting device 201 of this embodiment, the sensor 202includes a sensor surface (indication input surface) having a sizecorresponding to the size of the display screen 200D of the tablet-typeinformation terminal 200 and is formed by the first conductor group 211and the second conductor group 212 having optical transparency.

The first conductor group 211 and the second conductor group 212 mayhave a configuration in which the respective groups are disposed on thesame surface side of a sensor board, or may have a configuration inwhich the first conductor group 211 is disposed on one surface side ofthe sensor board and the second conductor group 212 is disposed on theother surface side.

The pen indication detecting circuit 203 is composed of a selectioncircuit 221 used as an input/output interface with the sensor 202, anamplifying circuit 222, a band-pass filter 223, a detection circuit 224,a sample/hold circuit 225, an AD (analog-to-digital) conversion circuit226, and a control circuit 220.

The selection circuit 221 selects a respective one conductor from thefirst conductor group 211 and the second conductor group 212 based on acontrol signal from the control circuit 220. The conductors selected bythe selection circuit 221 are connected to the amplifying circuit 222and a signal from the transmission-type electronic pen 1 is detected bythe selected conductors and is amplified by the amplifying circuit 222.The output of this amplifying circuit 222 is supplied to the band-passfilter 223 and only a component of the frequency of the signaltransmitted from the transmission-type electronic pen 1 is extracted.

An output signal of the band-pass filter 223 is subjected to detectionby the detection circuit 224. An output signal of this detection circuit224 is supplied to the sample/hold circuit 225 and is sampled and heldat predetermined timing based on a sampling signal from the controlcircuit 220. Thereafter, the signal is converted to a digital value bythe AD conversion circuit 226. The digital data from the AD conversioncircuit 226 is read by the control circuit 220 and is processed.

The control circuit 220 operates to send out a control signal to each ofthe sample/hold circuit 225, the AD conversion circuit 226, and theselection circuit 221 based on a program stored in a ROM (Read OnlyMemory) inside the control circuit 220. Furthermore, the control circuit220 calculates position coordinates on the sensor 202 indicated by thetransmission-type electronic pen 1 from digital data from the ADconversion circuit 226, and outputs data of the position coordinates toanother processor or the like in the tablet-type information terminal200.

FIGS. 3A-3C are a timing chart showing a signal of a predeterminedpattern from the transmission-type electronic pen 1 received by thesensor 202 of the position detecting device 201 in accordance with of anembodiment. The transmission-type electronic pen 1 of the embodimentincludes a control circuit 101 and a transmission circuit 102 as shownin FIG. 5 described below and the transmission circuit 102 repeatedlyoutputs a signal of the predetermined pattern based on a control signalfrom the control circuit 101. Furthermore, the transmission-typeelectronic pen 1 of the embodiment includes a writing pressure detectingmodule 7 described below as pressure detector that detects the pressureapplied to a core body (pen core). In this example, the writing pressuredetecting module 7 is formed of a variable-capacitance capacitor thatpresents capacitance according to the pressure (writing pressure)applied to the core body of the transmission-type electronic pen 1 (forexample, see Japanese Patent No. 2011-186803).

FIG. 3A is a diagram showing an example of the control signal from thecontrol circuit 101 of the transmission-type electronic pen 1. As shownin FIG. 3B, in a certain period during which the high level is kept, thetransmission-type electronic pen 1 continuously transmits a transmissionsignal from the transmission circuit 102 as a burst signal (continuoustransmission period in FIG. 3C).

The length of the continuous transmission period is set to time lengthwith which an indicated position on the sensor 202 by thetransmission-type electronic pen 1 can be detected in the pen indicationdetecting circuit 203 of the position detecting device 201. For example,the length is set to a time length during which all of the firstconductors 211Y and the second conductors 212X can be scanned one ormore times, preferably plural times or more.

In the continuous transmission period, the control circuit 101 of thetransmission-type electronic pen 1 detects the writing pressure appliedto the core body thereof as a detection signal according to thecapacitance of the variable-capacitance capacitor of the writingpressure detecting module 7, and obtains the writing pressure as a10-bit value (binary code) for example, from the detection signal.

Then, as shown in FIG. 3A, when the continuous transmission period ends,the control circuit 101 of the transmission-type electronic pen 1carries out ASK (Amplitude Shift Keying) modulation of the transmissionsignal from the transmission circuit 102 by controlling the controlsignal to the high level or low level at a predetermined cycle (Td). Atthis time, the control circuit 101 invariably sets the control signal tothe high level in the first round of the predetermined cycle (Td) andemploys it as a start signal in FIG. 3C. The start signal is a timingsignal for allowing the subsequent data transmission timing to beaccurately determined on the side of the position detecting device 201.It is also possible to utilize a burst signal as the timing signalinstead of the start signal.

The transmission-type electronic pen 1 sequentially transmits writingpressure data of 10 bits subsequently to the start signal. In this case,the transmission-type electronic pen 1 carries out control such that thecontrol signal is set to the low level and the transmission signal isnot sent out when the transmission data (binary code) is “0” and thecontrol signal is set to the high level and the transmission signal issent out when the transmission data (binary code) is “1.” In FIGS.3A-3C, the case in which the writing pressure data to be transmitted isshown to be “1010111010.” Subsequently to the writing pressure data, thetransmission-type electronic pen 1 sends out data of its ownidentification information, the remaining battery level, and so forth asan ASK signal or an OOK (On Off Keying) signal similar to the abovedescription. The transmission-type electronic pen 1 repeatedly transmitsthe signal of the pattern composed of the continuous transmission periodand the transmission period of the digital data like the above-describedperiods at a cycle based on control from the control circuit 101.

In the pen indication detecting circuit 203 of the position detectingdevice 201, first the control circuit 220 supplies a selection signal tothe selection circuit 221 to sequentially select the second conductors212X₁ to 212X_(n), for example. Furthermore, when each of the secondconductors 212X₁ to 212X_(n) is selected, the control circuit 220 readsa data output from the AD conversion circuit 226 as a signal level.Then, if the signal level of none of the second conductors 212X₁ to212X_(n) reaches a predetermined value, the control circuit 220determines that the transmission-type electronic pen 1 is not present onthe sensor 202, and repeats the control to sequentially select thesecond conductors 212X₁ to 212X_(n).

If a signal at a level equal to or higher than the predetermined valueis detected from any of the second conductors 212X₁ to 212X_(n), thecontrol circuit 220 stores the number of the second conductor 212X fromwhich the highest signal level is detected and plural second conductors212X around it. Then, the control circuit 220 controls the selectioncircuit 221 to sequentially select the first conductors 211Y₁ to211Y_(m), and reads the signal level from the AD conversion circuit 226.At this time, the control circuit 220 stores the numbers of the firstconductor 211Y from which the highest signal level is detected andplural first conductors 211Y around it.

Then, the control circuit 220 detects a position on the sensor 202indicated by the transmission-type electronic pen 1 from the number ofthe second conductor 212X and the number of the first conductor 211Yfrom which the highest signal level is detected and the plural secondconductors 212X and the plural first conductors 211Y around them, storedin the above-described manner.

After selecting the last first conductor 211Y_(m) by the selectioncircuit 221 and ending the detection of the signal level, the controlcircuit 220 waits for the end of the continuous transmission period fromthe transmission-type electronic pen 1. When detecting a start signalafter the end of the continuous transmission period, the control circuit220 carries out operations of reading writing pressure data and so forthand sends out the read writing pressure data, its own identificationinformation, the remaining battery level, and so forth as an ASK signalor an OOK (On Off Keying) signal as described above. Then, the controlcircuit 220 repeats the above operation.

[Mechanical Configuration of Transmission-type Electronic Pen 1 ofEmbodiment]

FIGS. 4A and 4B are diagrams showing the mechanical configuration of thetransmission-type electronic pen 1 in accordance with an embodiment.FIG. 4A is obtained by removing part of a case 2 (casing) of thetransmission-type electronic pen 1 and showing the inside thereof.Furthermore, FIG. 4B is an enlarged sectional view showing the internalconfiguration of the pen tip side, which is not shown in FIG. 4A.

The transmission-type electronic pen 1 includes the case 2 that forms acasing formed into a circular tubular shape elongated in the axialcenter direction. The case 2 is composed of a case main body 21 and afront cap 22 and a rear cap 23 joined to the case main body 21. The casemain body 21 and the front cap 22 are composed of anelectrically-conductive material, specifically aluminum in this example.The rear cap 23 is composed of a non-electrically-conductive material,specifically an insulating resin in this example.

At the end part of the front cap 22 on the pen tip side, a pen tip guardmember 24 composed of an insulating material is fitted and arranged. Acore body 4 is composed of an electrically-conductive material,specifically a resin into which metal powders are mixed in this example.As shown in FIG. 4B, the core body 4 is inserted into a through-hole 24a of the pen tip guard member 24 from an opening 1 a and is in a stateof being freely movable in the axial center direction.

In the hollow part of the case 2, a board holder 3, a battery 5, and acore body holder 6 are housed as shown in FIGS. 4A and 14B.

The board holder 3 is composed of an insulating resin(specifically aliquid crystal polymer, for example) and includes a holding part(hereinafter referred to as holding part for components for pressuresensing) 3 a for the writing pressure detecting module 7 as an exampleof pressure detector and a printed board placement base 3 b. Theposition of the board holder 3 is restricted so that the board holder 3may be prevented from moving to the side of the core body 4 in the axialcenter direction in the case 2.

A terminal conductor 51 that electrically abuts against a positiveterminal 5 a of the battery 5 is provided at the end part of the printedboard placement base 3 b on the side of the rear cap 23. This terminalconductor 51 is electrically connected to a copper foil pattern of apower supply line of a printed board 8. Furthermore, as shown in FIG.4A, at the press-fitting part of the rear cap 23 into the case main body21, a coil spring terminal 52 (that is composed of anelectrically-conductive metal that is electrically connected to anegative terminal 5 b of the battery 5 and is connected to an earthconductor of the printed board 8) is arranged. The earth conductor ofthe printed board 8 is not connected to the case main body 21 and thefront cap 22.

In this embodiment arranged on the printed board 8 are the transmissioncircuit 102 that generates a signal to be sent out from the core body 4of the transmission-type electronic pen 1, the control circuit 101 thatcontrols activation and the transmission operation state of thistransmission circuit 102, and so forth, and peripheral circuitcomponents thereof

Furthermore, in this embodiment, the case main body 21 and the front cap22, which are composed of an electrically-conductive material, areelectrically connected to the control circuit 101. The control circuit101 detects the state in which a user is in contact with the case mainbody 21 or the front cap 22, which is an electrical conductor, with ahand or finger and holds it by a so-called capacitive touch detectionmethod as described below.

The core body holder 6 is composed of an electrically-conductivematerial and has a shape in which a housing fitting part 61 in which anelectrically-conductive elastic member 9 composed ofelectrically-conductive rubber is fitted and housed and a bar-shapedpart 62 fitted to the writing pressure detecting module 7 aremonolithically formed, for example. The core body 4 is fitted to andheld by the core body holder 6 with the intermediary of theelectrically-conductive elastic member 9 but is configured to withdrawnfrom the core body holder part 6 through pulling by a predeterminedforce. The bar-shaped part 62 of the core body holder 6 is fitted to aholding member 73 described below in the writing pressure detectingmodule 7 in the holding part 3 a for components for pressure sensing inthe board holder 3.

A coil spring 13 composed of an electrically-conductive material, suchas an electrically-conductive metal, is mounted on the bar-shaped part62 of the core body holder 6, and the core body holder 6 is configuredto be always biased to the side of the core body 4 relative to the boardholder 3 by the coil spring 13.

Furthermore, in this embodiment, for the board holder 3, a member for anelectrical connection is formed by a conductor terminal member 14arranged to straddle the holding part 3 a for components for pressuresensing and the coil spring 13 composed of an electrically-conductivematerial. By this member for an electrical connection, an electricalconnection for signal supply from the transmission circuit 102 of theprinted board 8 is realized (see FIG. 4B). As shown in FIG. 4B, theconductor terminal member 14 is composed of an abutting plate part 141(against which one end of the coil spring 13 abuts) and an extendingpart 142 for connecting the abutting plate part 141 and a copper foilpart connected to a signal supply terminal of the transmission circuit102 of the printed board placement base 3 b across the part of theholding part 3 a for components for pressure sensing in the board holder3. A signal from the transmission circuit 102 is supplied to the corebody 4 inserted and fitted into the electrically-conductive elasticmember 9 via the conductor terminal member 14, the coil spring 13, thecore body holder 6, and the electrically-conductive elastic member 9.

The writing pressure detecting module 7 of this example is configuredwith a variable-capacitance capacitor whose capacitance changesaccording to the writing pressure applied to the core body 4. Thewriting pressure detecting module 7 in this embodiment is formed byusing a well-known variable-capacitance capacitor described in JapanesePatent Publication No. 2011-186803, for example.

Components for pressure sensing that form the writing pressure detectingmodule 7 of this example are composed of plural components including adielectric 71, a terminal member 72, the holding member 73, anelectrically-conductive member 74, and an elastic member 75, as shown inFIG. 4B. The holding part 3 a for components for pressure sensing in theboard holder 3 is formed of a tubular body 32 having a hollow part 31 asshown in FIG. 4B, and the components for pressure sensing that form thewriting pressure detecting module 7 are lined up in the axial centerdirection and are housed in the hollow part 31. A wall part 33 is formedbetween the holding part 3 a for components for pressure sensing and theboard holder part 3 b in the board holder 3.

The variable-capacitance capacitor formed as the writing pressuredetecting module 7 of this example is formed by sandwiching thedielectric 71 between the terminal member 72 that forms one electrode ofthe variable-capacitance capacitor and the electrically-conductivemember 74 that forms the other electrode. The terminal member 72 and theelectrically-conductive member 74 are connected to the copper foilpattern of the printed board 8 across the wall part 33.

Furthermore, the holding member 73 that holds theelectrically-conductive member 74 is configured to be movable in theaxial center direction in the tubular body 32. Moreover, the holdingmember 73 is always biased to the core body side by the elastic member75 formed of a coil spring composed of an electrically-conductivematerial. The electrically-conductive member 74 is electricallyconnected to the elastic member 75, and one end 75 a of the coil springthat forms the elastic member 75 is connected to the copper foil patternof the printed board 8 as the other electrode of thevariable-capacitance capacitor.

In the holding member 73, a recess 73 a is made on the same side as theside of the core body 4 in the axial center direction thereof as shownin FIG. 4B. The bar-shaped part 62 of the core body holder 6 ispress-fitted into the recess 73 a of the member 73 and is engaged so asnot to fall off to the side of the core body 4.

When a pressure is applied to the tip part of the core body 4, the corebody 4 and the core body holder 6 are displaced towards the rear cap 23in the axial center direction according to the pressure. Due to thisdisplacement, the holding member 73 in the holding part 3 a forcomponents for pressure sensing is displaced in a direction of thedielectric 71 against the elastic biasing force of the elastic member75. As a result, the electrically-conductive member 74 fitted to theholding member 73 is displaced towards the dielectric 71, so that thedistance between the electrically-conductive member 74 and thedielectric 71 and the contact area between the electrically-conductivemember 74 and the dielectric 71 change according to the pressure appliedto the core body 4. Due to this, the capacitance of thevariable-capacitance capacitor that forms the writing pressure detectingmodule 7 changes according to the pressure applied to the core body 4such that the change in the capacitance is detected by the controlcircuit 101 and the writing pressure is detected.

[Operation Control of Transmission-type Electronic Pen 1]

FIG. 5 is a block diagram showing a high level configuration of anelectronic circuit of the transmission-type electronic pen 1 inaccordance with an embodiment. The configuration is centered around theabove-described control circuit 101 and transmission circuit 102. Asshown in FIG. 5, the battery 5 is connected to a power supply circuit103. The source voltage of the transmission-type electronic pen 1 ofthis embodiment is generated by the power supply circuit 103 andsupplied to the control circuit 101 and transmission circuit 102. Inthis example, the control circuit 101 is formed as an IC (IntegratedCircuit).

The transmission circuit 102 internally includes an oscillator(diagrammatic representation is omitted) in this example and generatesand outputs a transmission signal based on an oscillation signal of theoscillator. In the example, the transmission signal from thetransmission circuit 102 is supplied to the core body 4, which is anelectrical conductor, and the transmission signal is transmitted to theposition detecting device 201 through the core body 4.

The control circuit 101 includes a microcomputer in this example andcontrols activation of the transmission operation of the transmissioncircuit 102 and controls the transmission operation state thereof. Inthis example, activation of the transmission operation of thetransmission circuit 102 includes activation of the built-in oscillator.Furthermore, in the control of the transmission operation state of thetransmission circuit of this example, amplitude control of theoscillation signal from the oscillator, control of the intermittence ofthe oscillation signal, and so forth are performed.

Furthermore, in this embodiment, the control circuit 101 detects contactby a user with the case main body 21 or the front cap 22 as anelectrical conductor with a hand or finger as a direct act of the userto the case 2 of the transmission-type electronic pen 1 (serving as atrigger for the start of use of the transmission-type electronic pen 1by the user) by detecting change in self-capacitance Cx of the case mainbody 21 and front cap 22 (see FIG. 5).

Here, the self-capacitance Cx of the case main body 21 and the front cap22 is the capacitance between the case main body 21 and front cap 22 andthe earth (ground) and includes floating capacitance. Furthermore, whena human body, such as a hand or finger, makes contact with the case mainbody 21 or the front cap 22, the human body is connected between thecase main body 21 and the front cap 22 and the ground. Due to this,capacitance corresponding to the human body is added to the floatingcapacitance when the human body is not in contact, and thus theself-capacitance Cx becomes higher. Therefore, the control circuit 101detects the change in this self-capacitance Cx and, accordingly, detectsthe contact of the hand or finger of the human body.

For this purpose, in this embodiment, the case main body 21 and thefront cap 22, which are an electrical conductor, are electricallyconnected to a first terminal P1 of the control circuit 101.Furthermore, a capacitor Cr is connected between the first terminal P1and a second terminal P2 of the control circuit 101 and the secondterminal P2 is grounded through a resistor Rc and a capacitor Cc.

In the control circuit 101, the self-capacitance Cx of the case mainbody 21 and the front cap 22 is measured as follows. Specifically, thecontrol circuit 101 sets the second terminal P2 to the high level toaccumulate a charge in the capacitor Cc, and thereafter sets the secondterminal P2 to high impedance to keep the charge in the capacitor Cc.

Next, the control circuit 101 sets the first terminal P1 and the secondterminal P2 to the low level to discharge part of the charge in thecapacitor Cc through the resistor Rc while discharging all of charges inthe self-capacitance Cx and the capacitor Cr.

Next, the control circuit 101 sets the first terminal P1 and the secondterminal P2 to high impedance to move the charge in the capacitor Cc tothe self-capacitance Cx and the capacitor Cr. Then, the control circuit101 compares the voltage across the self-capacitance Cx between thefirst terminal P1 and the earth and a reference voltage and determineswhether the voltage across the self-capacitance Cx is higher than thereference voltage. Thereby, the control circuit 101 detects contact ofthe hand or finger of the human body with the case main body 21 or thefront cap 22.

Furthermore, the control circuit 101 monitors the capacitance Cv of avariable-capacitance capacitor 7C formed of the writing pressuredetecting module 7 and determines whether the capacitance Cv of thevariable-capacitance capacitor 7C has become higher than a predeterminedreference capacitance. Thereby, the control circuit 101 detects that apressure is applied to the tip of the core body 4. For this purpose, inthis embodiment, a third terminal P3 of the control circuit 101 isconnected to ground through the variable-capacitance capacitor 7C and isconnected to ground through a resistor Rv.

Furthermore, the control circuit 101 carries out the following operationduring the continuous transmission period in described with reference toFIGS. 3A-3C and detects the capacitance Cv of the variable-capacitancecapacitor 7C. Specifically, first the control circuit 101 sets the thirdterminal P3 to the high level to charge the variable-capacitancecapacitor 7C. Thereafter, the control circuit 101 sets the thirdterminal P3 to high impedance to discharge the variable-capacitancecapacitor 7C through the resistor Rv. Thereupon, the potential of thethird terminal P3, i.e., the voltage across the variable-capacitancecapacitor 7C, gradually decreases. The time until the voltage across thevariable-capacitance capacitor 7C becomes the predetermined referencevoltage depends on the capacitance Cv of the variable-capacitancecapacitor 7C.

Therefore, the control circuit 101 obtains the capacitance Cv of thevariable-capacitance capacitor 7C by measuring the time until thevoltage across the variable-capacitance capacitor 7C becomes thepredetermined reference voltage. Then, from a change in the obtainedcapacitance Cv, the control circuit 101 determines whether a pressure isbeing applied to the core body 4 of the transmission-type electronic pen1.

Furthermore, in this embodiment, the control circuit 101 carries outactivation control and control of the transmission operation state forthe transmission circuit 102 of the transmission-type electronic pen 1based on whether a hand or finger of a human body has made contact withthe case main body 21 or the front cap 22 as an electrical conductor andwhether a pressure is being applied to the core body 4 of thetransmission-type electronic pen 1.

FIG. 6 is a diagram for showing mode transition based on control ofactivation and the transmission operation state of the transmissioncircuit 102 by the control circuit 101 in the transmission-typeelectronic pen 1 of the first embodiment.

In FIG. 6, in a sleep mode M0, the transmission circuit 102 is notactivated and is not transmitting a signal.

In a contact operation mode M1 the transmission circuit 102 is in thenormal transmission operation state in which a user holds thetransmission-type electronic pen 1 with a hand or fingers in order touse the transmission-type electronic pen 1 and the hand or finger of thehuman body is in contact with the case main body 21 or the front cap 22as the electrical conductor.

In a power saving mode (contact) M2 the transmission circuit 102 is in atransmission operation state with low power consumption in which a userholds the transmission-type electronic pen 1 with a hand or fingers andthe hand or finger of the human body is in contact with the case mainbody 21 or the front cap 22 as an electrical conductor. In thisembodiment, in the transmission operation state with low powerconsumption, the amplitude of the signal from the transmission circuit102 is set lower than the amplitude of the signal in the normaltransmission operation state in the contact operation mode M1.Alternatively, the repetition cycle of the signal in a pattern composedof the continuous transmission period and the transmission period ofdigital data shown in FIGS. 3A-3C is set longer than the repetitioncycle in the normal transmission operation state in the contactoperation mode M1.

In a normal operation mode (non-contact) M10, the transmission circuit102 is in the normal transmission operation state in which a user holdsthe transmission-type electronic pen 1 with a hand or fingers in orderto use the transmission-type electronic pen 1 but the control circuit101 cannot detect that the hand or finger of the human body is incontact with the case main body 21 or the front cap 22 as an electricalconductor because the user wears a glove, or the like.

In a power saving mode (non-contact) M20, the transmission circuit 102is in a transmission operation state with low power consumption in whichit is impossible to detect that a hand or finger of a human body is incontact with the case main body 21 or the front cap 22 as an electricalconductor because the user wears a glove, or the like. The transmissionoperation state with low power consumption in the transmission circuit102 is similar to the power saving mode (contact) M2.

Furthermore, in this embodiment, the control circuit 101 determineswhether a hand or finger of a human body is in contact with the casemain body 21 or the front cap 22 as an electrical conductor based onchange in the self-capacitance Cx of the case main body 21 and the frontcap 22 as the electrical conductor. In addition, the control circuit 101determines whether a pressure is being applied to the core body 4 of thetransmission-type electronic pen 1 based on a change in the capacitanceCv of the variable-capacitance capacitor 7C formed of the writingpressure detecting module 7. Based on this, the control circuit 101controls the transition of the plural modes shown in FIG. 6 regardingthe transmission circuit 102 of the transmission-type electronic pen 1.

FIG. 7 to FIG. 9 are show a flow diagram of a processing operation formode transition control of the transmission-type electronic pen 1 basedon control of the transmission circuit 102 by the control circuit 101.With reference to the flow diagram, the transition control of the pluralmodes of the transmission-type electronic pen 1 shown in FIG. 6 isdescribed below.

In a state in which a user is not intending to start use of thetransmission-type electronic pen 1 and, thus, a hand or finger of ahuman body is not in contact with the case main body 21 or the front cap22 as an electrical conductor and a pressure is not applied to the tipof the core body 4, the transmission-type electronic pen 1 is in thesleep mode M0 as a result of control performed by the control circuit101. In the sleep mode M0, the transmission circuit 102 is not activatedand is not transmitting a signal as described above. The flow diagram ofFIG. 7 to FIG. 9 starts from the sleep mode M0 state.

In the sleep mode M0, the control circuit 101 monitors change in theself-capacitance Cx of the case main body 21 and the front cap 22 (stepS1) and determines whether or not a hand or finger has made contact withthe case main body 21 or the front cap 22 (step S2) as described above.When determining, at step S2, that a hand or finger has made contactwith the case main body 21 or the front cap 22, the control circuit 101activates the transmission circuit 102 and carries out control totransition from the sleep mode M0 to the contact operation mode M1 (stepS3).

In the contact operation mode M1, the control circuit 101 carries outcontrol to cause the transmission circuit 102 to repeatedly transmit asignal of a pattern, such as the pattern described with reference toFIGS. 3A-3C, with a normal signal amplitude and a normal repetitioncycle. The normal signal amplitude and the normal repetition cycle are asignal amplitude and a repetition cycle with which the positiondetecting device 201 can receive the signal from the transmission-typeelectronic pen 1 and can detect an indicated position on the sensor 202thereof by the transmission-type electronic pen 1 surely and relativelyrapidly.

Next, in the contact operation mode M1, the control circuit 101 monitorsthe capacitance Cv of the variable-capacitance capacitor 7C forming thewriting pressure detecting module 7 and determines whether or not awriting pressure is being applied to the core body 4 (step S4) asdescribed above. When determining, at step S4, that a writing pressureis being applied to the core body 4, the control circuit 101 repeatsstep S4 and keeps the contact operation mode M1.

Furthermore, when determining, at step S4, that a writing pressure isnot being applied to the core body 4, the control circuit 101 monitorschange in the self-capacitance of the case main body 21 and the frontcap 22 and determines whether or not the hand or finger has beenseparated from the case main body 21 or the front cap 22 (step S5). Whendetermining in step S5 that the hand or finger has been separated fromthe case main body 21 or the front cap 22, the control circuit 101 stopsthe transmission of the transmission circuit 102 and carries out controlto return from the contact operation mode M1 to the sleep mode M0 (stepS6). Then, after step S6, the control circuit 101 returns the processingto step S1 and repeats the processing of step S1 and the subsequentsteps.

Furthermore, when determining at step S5 that the hand or finger has notbeen separated from the case main body 21 or the front cap 22, thecontrol circuit 101 determines whether or not the state in which awriting pressure is not applied to the core body 4 has continued for afirst predetermined time T1 or longer (step S7). The first predeterminedtime T1 is a time set in consideration of the fact that even when thecore body 4 of the transmission-type electronic pen 1 is separated fromthe input surface of the sensor 202 of the position detecting device (asa result of user action) and a writing pressure is not applied to thecore body 4 (as a result of user action), the user brings thetransmission-type electronic pen 1 into contact with the input surfaceof the sensor 202 again to indicate input after a comparatively-shorttime. For example, T1 is set to equal 30 seconds.

Then, when determining at step S7 that the state in which a writingpressure is not applied to the core body 4 has not continued for thefirst predetermined time T1 or longer, the control circuit 101 returnsthe processing to step S4 and executes the processing of step S4 andsubsequent steps.

Furthermore, when determining at the step S7 that the state in which awriting pressure is not applied to the core body 4 has continued for thefirst predetermined time T1 or longer, the control circuit 101 performscontrol to transition from the contact operation mode M1 to the powersaving mode (contact) M2, in which the transmission operation of thetransmission circuit 102 is maintained but the consumption of thebattery 5 is reduced (step S11 in FIG. 8). Specifically, in thisembodiment, in the power saving mode (contact), the transmission circuit102 realizes power saving by setting the amplitude of the transmittedsignal lower than in the normal transmission operation state or settingthe repetition cycle of the signal of the pattern composed of theabove-described continuous transmission period and digital datatransmission period longer than in the normal transmission operationstate as described above.

If the mode is immediately switched to the power saving mode M2 when thestate in which a writing pressure is not applied to the core body 4 isobtained without waiting for the elapse of the predetermined time T41,when a user attempts to return the state from the non-contact state ofthe core body 4 of the relevant transmission-type electronic pen 1 tothe contact state of the core body 4 in a short time to carry outposition indication, return from the power saving mode M2 to the contactoperation mode M1 is necessary in the transmission-type electronic pen 1and, thus, there is a fear that the response corresponding to theposition indication by the transmission-type electronic pen 1 isdelayed. However, in this embodiment, a transition is not made from thecontact operation mode M1 to the power saving mode M2 during the firstpredetermined time T1 and, therefore, such a problem in the response canbe alleviated.

Next, the control circuit 101 monitors change in the self-capacitance ofthe case main body 21 and the front cap 22 and determines whether or notthe hand or finger has been separated from the case main body 21 or thefront cap 22 (step S12). When determining at step S12 that the hand orfinger has been separated from the case main body 21 or the front cap22, the control circuit 101 stops the transmission operation of thetransmission circuit 102 and carries out control to transition from thepower saving mode (contact) M2 to the sleep mode M0 (step S13).Thereafter, the control circuit 101 returns the processing to step S1and repeats the processing of step S1 and the subsequent steps.

Furthermore, when determining at step S12 that the hand or finger hasnot been separated from the case main body 21 or the front cap 22, thecontrol circuit 101 monitors the capacitance Cv of thevariable-capacitance capacitor 7C forming the writing pressure detectingmodule 7 and determines whether or not a writing pressure is beingapplied to the core body 4 (step S14). Then, when determining at stepS14 that a writing pressure is being applied to the core body 4, thecontrol circuit 101 proceeds to step S3 and carries out control totransition from the power saving mode (contact) M2 to the contactoperation mode M1.

Moreover, when determining at step S14 that a writing pressure is notbeing applied to the core body 4, the control circuit 101 determineswhether or not the state in which a writing pressure is not applied tothe core body 4 has continued for a second predetermined time T2 (T1<T2)or longer (step S15).

Here, the second predetermined time T2 is a time set accounting for thefact when a user is absorbed in thought, or the like, although holdingthe transmission-type electronic pen 1 with a hand or fingers and it isguessed that the user does not immediately carry out position indicationto the input surface of the sensor 202 of the position detecting device201 by the transmission-type electronic pen 1 and therefore it ispreferable to switch the mode to the power saving mode to prevent thedraining of the battery 5. For example, T2 may be set to equal fiveminutes.

Furthermore, when determining at step S15 that the state in which awriting pressure is not applied to the core body 4 has not continued forthe second predetermined time T2 or longer, the control circuit 101keeps the power saving mode (contact) M2 and returns to step S12 toexecute the processing of step S12 and the subsequent steps.

When determining at step S15 that the state in which a writing pressureis not applied to the core body 4 has continued for the secondpredetermined time T2 or longer, the control circuit 101 stops thetransmission operation of the transmission circuit 102 and carries outcontrol to transition from the power saving mode (contact) M2 to thesleep mode M0 (step S16). Thereafter, the control circuit 101 returns tostep S1 and repeats step S1 and the subsequent steps.

In the above-described manner, in this embodiment, when it is determinedthat the state in which a writing pressure is not applied to the corebody 4 has continued for the second predetermined time T2 or longer, atransition is made from the state of the power saving mode (contact) tothe sleep mode M0 and, thus, useless power consumption of the battery 5can be alleviated.

Furthermore, when determining at step S2 in FIG. 7 that the contact ofthe hand or finger of the user with the case main body 21 or the frontcap 22 based on change in the self-capacitance Cx of the case main body21 and the front cap 22 has not been detected, the control circuit 101monitors the capacitance Cv of the variable-capacitance capacitor 7Cforming the writing pressure detecting module 7 and determines whetheror not a writing pressure is not being applied to the core body 4 (stepS21 in FIG. 9).

If a user wears a glove for example and holds the transmission-typeelectronic pen 1 and brings the core body 4 into contact with the inputsurface of the sensor 202 of the position detecting device 201 to applya writing pressure, the contact of a hand or finger of the user with thecase main body 21 or the front cap 22 based on change in theself-capacitance of the case main body 21 and the front cap 22 is notdetected due to the glove. However, due to the application of thewriting pressure to the core body 4, it turns out that positionindication is being attempted on the input surface of the sensor 202 ofthe position detecting device 201 by the relevant transmission-typeelectronic pen 1. At step S21, it is determined whether use of thetransmission-type electronic pen 1 by a user who wears such a glove orthe like has started.

When determining at step S21 that a writing pressure is not beingapplied to the core body 4, the control circuit 101 keeps the sleep modeand returns to step S1.

Furthermore, when determining at step S21 that a writing pressure isapplied to the core body 4, the control circuit 101 activates thetransmission circuit 102 and carries out control to make a transitionfrom the sleep mode M0 to the normal operation mode (non-contact) M10(step S23). In the normal operation mode (non-contact) M10 of step S23,the control circuit 101 controls the transmission circuit 102 to causethe transmission circuit 102 to repeatedly transmit a signal of apattern, such as the pattern described with reference to FIGS. 3A-3C,with the normal signal amplitude and the normal repetition cycle similarto the contact operation mode M1.

Moreover, in this normal operation mode (non-contact) M10, the controlcircuit 101 monitors the capacitance Cv of the variable-capacitancecapacitor 7C forming the writing pressure detecting module 7 anddetermines whether or not the writing pressure applied to the core body4 has disappeared (step S24). When determining at step S24 that thewriting pressure applied to the core body 4 has not disappeared, thecontrol circuit 101 keeps the normal operation mode (non-contact) M10(step S25). Then, the control circuit 101 returns to step S24.

When determining at step S24 that the writing pressure applied to thecore body 4 has disappeared, the control circuit 101 determines whetheror not the state in which a writing pressure is not applied to the corebody 4 has continued for the first predetermined time T1 or longer,specifically for 30 seconds or longer for example (step S26). Whendetermining at step S26 that the state in which a writing pressure isnot applied to the core body 4 has not continued for the firstpredetermined time T1 or longer, the control circuit 101 monitors changein the self-capacitance Cx of the case main body 21 and the front cap 22and determines whether or not a hand or finger has directly made contactwith the case main body 21 or the front cap 22 (step S27).

When determining in the step S27 that a hand or finger has not directlymade contact with the case main body 21 or the front cap 22, the controlcircuit 101 returns the processing to step S24. Furthermore, whendetermining at step S27 that a hand or finger has directly made contactwith the case main body 21 or the front cap 22, the control circuit 101returns the processing to step S3 in FIG. 7 and executes the processingstep S3 and subsequent steps.

Furthermore, when determining in the step S26 that the state in which awriting pressure is not applied to the core body 4 has continued for thefirst predetermined time T1 or longer, the control circuit 101 carriesout control to transition from the normal operation mode (non-contact)M10 to the power saving mode (non-contact) M20, in which thetransmission operation of the transmission circuit 102 is kept but theconsumption of the battery is reduced (step S28). In this power savingmode (non-contact), similar to the case of the above-described powersaving mode (contact), the transmission circuit 102 realizes powersaving by setting the amplitude of the transmitted signal lower than inthe normal transmission operation state or setting the repetition cycleof the signal of the pattern composed of the above-described continuoustransmission period and digital data transmission period longer than inthe normal transmission operation state.

Next, the control circuit 101 determines whether or not the state inwhich a writing pressure is not applied to the core body 4 has continuedfor the second predetermined time T2 or longer, specifically T2=fiveminutes or longer, for example (step S29). When determining at step S29that the state in which a writing pressure is not applied to the corebody 4 has continued for the second predetermined time T2 or longer, thecontrol circuit 101 stops the transmission operation from thetransmission circuit 102 and carries out control to make a transitionfrom the power saving mode (non-contact) M20 to the sleep mode M0 (stepS30). Thereafter, the control circuit 101 returns to step S1 and repeatsstep S1 and subsequent steps.

When determining at step S29 that the state in which a writing pressureis not applied to the core body 4 has not continued for the secondpredetermined time T2 or longer, the control circuit 101 monitors thecapacitance Cv of the variable-capacitance capacitor 7C forming thewriting pressure detecting module 7 and determines whether or not awriting pressure is being applied to the core body 4 (step S31). Then,when determining at step S31 that a writing pressure is being applied tothe core body 4, the control circuit 101 returns to step S23 and carriesout control to transition from the power saving mode (non-contact) M20to the normal operation mode (non-contact) M10. Thereafter, the controlcircuit 101 executes step S23 and subsequent steps.

When determining at step S31 that a writing pressure is not beingapplied to the core body 4, the control circuit 101 monitors change inthe self-capacitance Cx of the case main body 21 and the front cap 22and determines whether or not a hand or finger has directly gottencontact with the case main body 21 or the front cap 22 (step S32).

When determining at step S32 that a hand or finger has not directlygotten contact with the case main body 21 or the front cap 22, thecontrol circuit 101 keeps the power saving mode (non-contact) M20 (stepS23) and then returns to step S29 to execute the processing of step S29and subsequent steps. Furthermore, when determining at step S32 that ahand or finger has not directly made contact with the case main body 21or the front cap 22, the control circuit 101 returns the processing tothe step S3 in FIG. 7 and executes the processing of step S3 andsubsequent steps.

[Effects of First Embodiment]

According to the transmission-type electronic pen 1 of theabove-described first embodiment, when contact of a hand or finger of auser with the case main body 21 or the front cap 22 composed of aconductor is detected by a detector as a direct act of the user to thecase 2, serving as a trigger for the start of use of thistransmission-type electronic pen 1, the transmission circuit 102 isactivated and is set to the first transmission operation state as thenormal transmission operation state in which an indicated position canbe surely detected by the position detecting device 201. Thus, when theuser intends to start use of the transmission-type electronic pen 1,detection of the hover state of the transmission-type electronic pen 1by the position detecting device 201 can be allowed to be alwayspossible.

Furthermore, according to the transmission-type electronic pen 1 of thisfirst embodiment, the control circuit 101 can control the transmissionoperation of the transmission circuit 102 so that further power savingcan be achieved, based on a detection output of the detector thatdetects contact by a hand or finger with the case main body 21 or thefront cap 22 as the conductor as a direct act of the user to the case 2,serving as a trigger for the start of use of this transmission-typeelectronic pen 1, and a writing pressure detection output about whethera writing pressure is being applied to the tip of the core body 4.

Specifically, even in the state in which a user is holding thetransmission-type electronic pen 1 of the embodiment, when the state inwhich a writing pressure is not applied to the transmission-typeelectronic pen 1 has continued for the first predetermined time T1 orlonger according to the writing pressure detection output, useless powerconsumption can be reduced as much as possible by offering further powersaving through decreasing the amplitude of the transmission signal ofthe transmission circuit 102 or increasing the repetition cycle of thetransmission signal of the predetermined pattern. Furthermore, when thestate in which a writing pressure is not applied to thetransmission-type electronic pen 1 has reached at least the secondpredetermined time T2 longer than the first predetermined time T1, themode is switched to the sleep mode in which the transmission of thetransmission circuit 102 is stopped and thus further power saving can beachieved.

Moreover, in the above-described first embodiment, even when a userholds the transmission-type electronic pen 1 while wearing a glove, thetransmission circuit 102 is activated based on the writing pressuredetection output. Thus, use of the transmission-type electronic pen 1can be ensured even when contact with the case main body 21 or the frontcap 22 cannot be detected. Furthermore, in this embodiment, also when aglove is worn, the transmission operation state of the transmissioncircuit is controlled in the above-described manner according to theresult of comparison between the continuation time of the state in whichcontact of the transmission-type electronic pen 1 with the sensorsurface is not detected based on the writing pressure detection outputand the first predetermined time T1 and the second predetermined timeT2. Thus, in the transmission-type electronic pen 1, useless powerconsumption can be reduced as much as possible.

Furthermore, in the above-described embodiment, after a writing pressureis detected once, even when the transmission-type electronic pen 1 isseparated from the surface of the sensor 202 of the position detectingdevice 201 and the detection of the writing pressure becomes absent, thetransmission circuit 102 continues the transmission operation until thepredetermined time T1 elapses in the state in which the detection of thewriting pressure is absent. In addition, in the above-described firstembodiment, after the elapse of the first predetermined time T1, thetransmission of the transmission circuit 102 is not immediately stoppedand a transition is made to the power saving mode in which thetransmission state is at such a degree that the hover state of thetransmission-type electronic pen 1 over the surface of the sensor 202 ofthe position detecting device 201 can be detected. Then, thetransmission state of the transmission circuit 102 is stopped when thestate in which the detection of the writing pressure is absent furthercontinues for at least the second predetermined time T2 longer than thefirst predetermined time T1.

Compared with the case in which the transmission of the transmissioncircuit 102 is immediately stopped when the state in which detection ofa writing pressure is absent continues for the predetermined time orlonger, in the case of the above-described first embodiment, the mode iscontrolled to two stages with the intermediary of the power saving modeand thus there are merits that power saving control can be carried outmore finely and that the response of detection in the position detectingdevice 201 for a position indication on the surface of the sensor 202 ofthe position detecting device 201 by the transmission-type electronicpen 1 becomes favorable also because detection of the hover state in thepower saving mode is possible.

In the state when detection of a writing pressure becomes absent, thereis not only the case in which the user immediately inputs positionindication again by the transmission-type electronic pen 1 but also thecase in which the user releases the transmission-type electronic pen 1from a hand and does not immediately input position indication again.However, according to the above-described embodiment, both cases arediscriminated and useless power consumption can be reduced as much aspossible while the original function of position indication by thetransmission-type electronic pen 1 is favorably kept.

Furthermore, in the above-described embodiment, detection of contact ofa human body, which is an electrical conductor, with the case main body21 or the front cap 22 is carried out by detecting change in theself-capacitance Cx of the case main body 21 and the front cap 22, whichare an electrical conductor. Therefore, transmission and reception of asignal as in the case of detecting mutual capacitance are unnecessaryand there is an effect that this configuration is suitable also forpower saving.

[Modification Example of First Embodiment]

In the above-described first embodiment, when determining that a hand orfinger of a user has made contact with the case main body 21 or thefront cap 22, the control circuit 101 transitions from the sleep mode M0to the contact operation mode M1 and causes the transmission circuit 102to carry out transmission in the normal operation state. However, whendetermining that a hand or finger of a user has made contact with thecase main body 21 or the front cap 22, the control circuit 101 maytransition from the sleep mode M0 to the power saving mode (contact) M2and, thereafter, may carry out control to make a transition from thepower saving mode (contact) M2 to the contact operation mode M1 whendetermining that a writing pressure is applied to the core body 4 in thepower saving mode (contact) M2. Also in this case, in the power savingmode (contact) M2, the transmission circuit 102 is in the transmissionoperation state that allows detection of the hover state of thetransmission-type electronic pen 1 by the position detecting device.Therefore, it is possible the detection of the hover state of thetransmission-type electronic pen 1 by the position detecting device canbe always possible when a user intends to start use.

Furthermore, in the above-described example, one stage of the powersaving mode is employed. However, the power saving mode may be set atplural stages having different degrees of power savings. It goes withoutsaying that the sleep mode is the mode in which transmission is stoppedand, therefore, is a mode of power saving.

Moreover, in the above-described example, when the state in which awriting pressure is not applied to the transmission-type electronic pen1 has reached at least the first predetermined time T1 in the contactoperation mode M1 or the normal operation mode M10, a transition is madeto the power saving mode M2 or M20. Furthermore, when the secondpredetermined time T2 or longer elapses, a transition is made from thepower saving mode M2 or M20 to the sleep mode M0. However, when thepredetermined time or longer elapses in the state in which a writingpressure is not applied to the transmission-type electronic pen 1 in thecontact operation mode M1 or the normal operation mode M10, a transitionmay be made directly to the sleep mode M0 without going through thepower saving mode M2 or M20.

Second Embodiment

In the above-described first embodiment, only contact of a human bodysuch as a hand or finger of a user with the case main body 21 or thefront cap 22 is detected as a direct act of the user to the case 2 ofthe transmission-type electronic pen 1, serving as a trigger for thestart of use of the transmission-type electronic pen. However, not onlycontact of a human body such as a hand or finger of a user with the casemain body 21 or the front cap 22 but the motion of the transmission-typeelectronic pen 1 due to an act such as raising after holding by a usermay be detected in combination as a direct act of the user to the case 2of the transmission-type electronic pen 1, serving as a trigger for thestart of use of the transmission-type electronic pen.

FIG. 10 is a block diagram of a high level configuration of anelectronic circuit of a transmission-type electronic pen 1A of thesecond embodiment. The mechanical structure of the transmission-typeelectronic pen 1A of this second embodiment is the same as theabove-described first embodiment. In the second embodiment, a gyrosensor 104 is arranged to be placed on the printed board 8 in the case 2in order to detect the motion of the case 2 of the transmission-typeelectronic pen 1A. Furthermore, as shown in FIG. 10, the gyro sensor 104is connected to the control circuit 101 and is configured to supply amotion detection output thereof to the control circuit 101.

Moreover, in the second embodiment, the control circuit 101 does notmake a transition from the sleep mode M0 to the contact operation modeM1 in response to only contact of a user with the case main body 21 orthe front cap 22 with a hand or finger. The control circuit 101 carriesout control to transition from the sleep mode M0 to the contactoperation mode M1 when the motion of the case 2 of the transmission-typeelectronic pen 1A is detected based on the motion detection output ofthe gyro sensor 104 in addition to the above-described contact of a handor finger.

Furthermore, in the second embodiment, even in the state in whichcontact of a hand or finger with the case main body 21 or the front cap22 by a user has not been detected, the control circuit 101 carries outcontrol to transition from the sleep mode M0 to the normal operationmode (non-contact) M10 when detecting the motion of the case 2 of thetransmission-type electronic pen 1A based on the motion detection outputof the gyro sensor 104. Therefore, in the second embodiment, when a userwears a glove and intends to start position indication while holding thetransmission-type electronic pen 1A, the hover state of thetransmission-type electronic pen 1A over the sensor of the positiondetecting device can be detected.

Moreover, in the second embodiment, the control circuit 101 considersthe motion detection output of the gyro sensor 104 in combination with atransition from the contact operation mode M1 to the power saving mode(contact) M2 and a transition from the normal operation mode(non-contact) M10 to the power saving mode (non-contact) M20.Specifically, in this second embodiment, even when the predeterminedtime T1 or longer elapses in the state in which detection of a writingpressure is absent, the control circuit 101 deems that an intention ofthe user to carry out position indication exists and does not make atransition to the power saving mode (contact) M2 or the power savingmode (non-contact) M20 when determining that the transmission-typeelectronic pen 1A is moving based on the motion detection output of thegyro sensor 104. That is, the control circuit 101 carries out atransition from the contact operation mode M1 to the power saving mode(contact) M2 or a transition from the normal operation mode(non-contact) M10 to the power saving mode (non-contact) M20 whendetermining that a predetermined time T1′ or longer has elapsed in thestate in which both of the detection output in the state in whichdetection of a writing pressure is absent and the state in which thetransmission-type electronic pen 1A is not moving based on the motiondetection output of the gyro sensor 104 are satisfied. In this case, thepredetermined time T1′ may be the same as the above-describedpredetermined time T1 or may be made different.

Furthermore, in the second embodiment, also in a transition from thepower saving mode (contact) M2 or the power saving mode (non-contact)M20 to the sleep mode M0, the motion detection output of the gyro sensor104 is also referenced similarly to the cases of a transition from thecontact operation mode M1 to the power saving mode (contact) M2 and atransition from the normal operation mode (non-contact) M10 to the powersaving mode (non-contact) M20.

In the above-described manner, according to the second embodiment, modetransition is controlled while considering the motion of the case 2 ofthe transmission-type electronic pen 1A. This enables power savingcontrol while considering an intention to use the transmission-typeelectronic pen 1A by the user.

[Modification Example of Second Embodiment]

In the above-described second embodiment, the control circuit 101 makesa transition from the sleep mode M0 to the contact operation mode M1based on detection of not only contact of a human body, such as a handor finger of a user with the case main body 21 or the front cap 22, butthe motion of the transmission-type electronic pen 1 due to an act suchas raising after holding by the user in combination. However, thefollowing way may be employed.

Specifically, the control circuit 101 may not make a transition to thecontact operation mode M1 but may make a transition to the power savingmode (contact) M2 when determining that a human body, such as a hand orfinger of a user, has made contact with the case main body 21 or thefront cap 22. Then, the control circuit 101 makes a transition from thepower saving mode (contact) M2 to the contact operation mode M1 whendetecting the motion of the transmission-type electronic pen 1 based onthe motion detection output of the gyro sensor 104.

Furthermore, the control circuit 101 does not transition to the normaloperation mode (non-contact) M10 but transitions to the power savingmode (non-contact) M20 when determining that the transmission-typeelectronic pen 1 has moved based on the motion detection output of thegyro sensor 104 without determining that a human body, such as a hand orfinger of a user, has made contact with the case main body 21 or thefront cap 22 in the sleep mode M0. Then, the control circuit 101 makes atransition from the power saving mode (non-contact) M20 to the normaloperation mode (non-contact) when detecting application of a writingpressure.

This can achieve further power saving. Furthermore, in the power savingmode (contact) M2 and the power saving mode (non-contact) M20, thetransmission signal of the transmission circuit 102 is in such a statethat the hover state of the transmission-type electronic pen 1A can bedetected by the position detecting device. Thus, also in thismodification example of the second embodiment, the user can enjoy theeffect that the hover state of the transmission-type electronic pen 1Acan be always detected by the position detecting device.

In the above-described second embodiment, the gyro sensor 104 is used asa unit for motion detection. However, an acceleration sensor or ageomagnetic sensor may be used instead of the gyro sensor. Furthermore,the gyro sensor, acceleration sensor, and geomagnetic sensor may be usedin combination.

Third Embodiment

In a third embodiment, the control circuit 101 detects only the motionof the transmission-type electronic pen 1 due to an act, such as raisingthe transmission-type electronic pen 1 after holding it by a user,without detecting contact of a human body such as a hand or finger ofthe user as a direct act of the user to the case 2 of thetransmission-type electronic pen 1, serving as a trigger for the startof use of the transmission-type electronic pen.

The mechanical structure of a transmission-type electronic pen 1A of thethird embodiment is the same as that of the above-described firstembodiment. Furthermore, the configuration of the electronic circuit ofthe major part of the transmission-type electronic pen of the thirdembodiment is a configuration obtained by omitting the detecting circuitpart for contact of a hand or finger of a user with the case main body21 or the front cap 22 for the control circuit 101 in FIG. 10 and,therefore, diagrammatic representation thereof is omitted here.

Furthermore, in the third embodiment, there is no need to discriminatebetween the contact operation mode M1 and the normal operation mode(non-contact) M10. Furthermore, there is no need to discriminate betweenthe power saving mode (contact) and the power saving mode (non-contact)M20. Therefore, mode transition is as shown in FIG. 11. In FIG. 11, asleep mode M0′ is in the same state as the above-described sleep modeM0. Furthermore, a normal operation mode M10′ is in the same state asthe above-described normal operation mode (non-contact) M10. Moreover, apower saving mode M20′ is in the same state as the above-described powersaving mode (non-contact) M20. The mode transition among them isdifferent from the above-described embodiment.

In the third embodiment, when detecting the motion of the case 2 of thetransmission-type electronic pen based on the motion detection output ofthe gyro sensor 104 in the sleep mode M0, the control circuit 101carries out control to transition from the sleep mode M0′ to the normaloperation mode M10′. In the third embodiment, when detectingpredetermined magnitude of motion based on the motion detection outputof the gyro sensor 104, the control circuit 101 immediately detects thatthe case 2 of the transmission-type electronic pen has moved. On theother hand, the control circuit 101 detects that the case 2 of thetransmission-type electronic pen is not moving when the control circuit101 has not detected the predetermined magnitude of motion continuouslyfor a predetermined time, specifically 30 seconds, for example, based onthe motion detection output of the gyro sensor 104.

When determining that the case 2 of the transmission-type electronic penis not moving in the normal operation mode M10′, the control circuit 101transitions from the normal operation mode M10′ to the sleep mode M0′.Then, the control circuit 101 transitions from the normal operation modeM10′ to the power saving mode M20′ when determining in the normaloperation mode M10′ that the state in which a writing pressure cannot bedetected continues for the predetermined time T1 (for example, 30seconds) or longer although the case 2 of the transmission-typeelectronic pen is moving.

When detecting that the case 2 of the transmission-type electronic penis not moving in the power saving mode M20′, the control circuit 101transitions from the power saving mode M20′ to the sleep mode M0′.Furthermore, also when determining that the state in which a writingpressure cannot be detected continues for the predetermined time T2 (forexample, five minutes) or longer although the case 2 of thetransmission-type electronic pen is moving in the power saving modeM20′, the control circuit 101 transitions from the power saving modeM20′ to the sleep mode M0′. Then, the control circuit 101 transitionsfrom the power saving mode M20′ to the normal operation mode M10′ whendetermining that the case 2 of the transmission-type electronic pen ismoving and a writing pressure can be detected in the power saving modeM20′.

Also in the third embodiment, detection of the hover state of thetransmission-type electronic pen 1 by the position detecting device canbe allowed to be always possible when the user intends to start use.Furthermore, according to the transmission-type electronic pen of thethird embodiment, the control circuit 101 can control the transmissionoperation of the transmission circuit 102 to achieve further powersaving based on the detection output of the motion of the case 2 of thetransmission-type electronic pen as a direct act of a user to thecasing, serving as a trigger for the start of use of thetransmission-type electronic pen, and writing pressure detection outputabout whether a writing pressure is being applied to the tip of the corebody 4.

Moreover, in the third embodiment, the transmission circuit 102 isactivated based on the motion detection output of the case 2 also when auser holds the transmission-type electronic pen 1 while wearing a glove.Thus, the position detecting device can detect also the hover state ofthe transmission-type electronic pen and can carry out power savingcontrol so that useless power consumption can be reduced as much aspossible.

[Other Embodiments]

Fourth Embodiment

The method for detecting contact of a hand or finger of a user with thecase main body 21 or the front cap 22 of the transmission-typeelectronic pens 1 and 1A in the above-described first and secondembodiments is a method in which change in the self-capacitance Cx ofthe case main body 21 and the front cap 22 composed of a conductor isdetected. The change in this self-capacitance Cx is according to thecontact area of the hand or fingers of the user to the case main body 21and the front cap 22.

Regarding the state of holding of the transmission-type electronic penby the user, when the user intends to tightly hold the transmission-typeelectronic pen and carry out position indication, the contact area of ahand or fingers of the user to the case main body 21 and the front cap22 becomes large. On the other hand, when the user merely picks up thetransmission-type electronic pen, the contact area of a hand or fingersof the user to the case main body 21 and the front cap 22 iscomparatively small.

In view of the above, the control circuit 101 may determine the contactarea of a hand or fingers of a user to the case main body 21 and thefront cap 22 from the magnitude of change in the self-capacitance Cx ofthe case main body 21 and the front cap 22, and control the transmissionoperation state of the transmission circuit 102 based on thedetermination result.

For example, the control circuit 101 controls the transmission circuit102 to the state of the power saving mode when the contact area of ahand or fingers of a user to the case main body 21 and the front cap 22is comparatively small and the control circuit 101 determines that thepresent state is the state in which the user is merely picking up thetransmission-type electronic pen. Furthermore, the control circuit 101controls the transmission circuit 102 to cause the transmission circuit102 to become the normal operation state when the contact area of thehand or fingers of the user to the case main body 21 and the front cap22 becomes large and the control circuit 101 determines that the presentstate is the state in which the user tightly holds the transmission-typeelectronic pen and intends to start position indication.

Fifth Embodiment

In the above-described first and second embodiments, almost the whole ofthe case 2 of the transmission-type electronic pens 1 and 1A is composedof a conductor for detection of contact by a hand or finger of a user.However, only one part of the case 2 expected to be held when a userstarts use of the transmission-type electronic pen 1 or 1A may becomposed of a conductor. For example, as shown with oblique lines inFIG. 12A, a configuration may be made in which a conductor is employedonly for a half part 2Ba (including the front cap 22) on the side of thecore body 4 in the axial center direction in a tubular case 2B of atransmission-type electronic pen 1B having the same configuration as thetransmission-type electronic pen 1. Furthermore, as shown with obliquelines in FIG. 12B, a configuration may be made in which a conductor isemployed only for a part 2Ca that is a part of half or less on the sideof the core body 4 in the axial center direction in a tubular case 2C ofa transmission-type electronic pen 1C having the same configuration asthe transmission-type electronic pen 1 and is except for the partequivalent to the front cap 22. The parts 2Ba and 2Ca of the case 2B arenot connected to but separated from the earth conductor of the printedboard 8.

Sixth Embodiment

Furthermore, the control circuit 101 may control the transmissionoperation state of the transmission circuit 102 according to theposition with which a user brings a hand or finger into contact in theaxial center direction in the conductor part of the case 2 of thetransmission-type electronic pen.

FIGS. 13A to 13C are diagrams showing examples of transmission-typeelectronic pens 1D, 1E, and 1F in which the control circuit 101 controlsthe transmission operation state of the transmission circuit 102according to the position with which a user brings a hand or finger intocontact in the axial center direction.

In the transmission-type electronic pen 1D of the example of FIG. 13A, acase 2D is composed of an insulator 2DI at substantially the centralpart in the axial center direction, a conductor 2Da on the side of thecore body 4 relative to this insulator 2DI, and a conductor 2Db on theopposite side to the side of the core body 4. Furthermore, the circuitis configured such that the respective conductors 2Da and 2Db areseparately connected to the control circuit 101 such that change inself-capacitance can be detected in the control circuit 101 based on aconfiguration similar to the above-described configuration.

In this example of FIG. 13A, when a user holds the part of the conductor2Db with a hand or fingers, it can be guessed that merely thetransmission-type electronic pen 1D is picked up, and therefore thecontrol circuit 101 carries out control to set the transmission circuit102 to the state of the power saving mode. Furthermore, when a userholds the part of the conductor 2Da with a hand or fingers, it can beguessed that the user intends to carry out position indication by thetransmission-type electronic pen 1D, and, therefore, the control circuit101 carries out control to set the transmission circuit 102 to thenormal transmission operation state.

In the transmission-type electronic pen 1E of the example of FIG. 13B,in a case 2E, a part on the side of the core body 4 as almost half inthe axial center direction is composed of a conductor. An insulator 2E1is used for substantially the central part of the conductor part and theconductor part is separated into a conductor 2Ea on the side of the corebody 4 and a conductor 2Eb on the opposite side to the side of the corebody 4 by this insulator 2E1. Furthermore, the circuit is configured sothat the respective conductors 2Ea and 2Eb are separately connected tothe control circuit 101 such that change in self-capacitance can bedetected in the control circuit 101 based on a configuration similar tothe above-described configuration.

In this example of FIG. 13B, when a user holds the part of the conductor2Eb with a hand or fingers, it can be guessed that the user is merelyholding the transmission-type electronic pen 1E and the state forcarrying out position indication by the transmission-type electronic pen1E has not yet been established, and therefore the control circuit 101carries out control to set the transmission circuit 102 to the state ofthe power saving mode. Furthermore, when a user holds the part of theconductor 2Ea with a hand or fingers, it can be guessed that the userintends to carry out position indication by the transmission-typeelectronic pen, and therefore the control circuit 101 carries outcontrol to set the transmission circuit 102 to the normal transmissionoperation state.

In the transmission-type electronic pen IF of the example of FIG. 13C,in a case 2F, three conductors 2Fa, 2Fb, and 2Fc are formed tosubstantially trisect the case 2F in the axial center direction. In thiscase, the conductors 2Fa and 2Fb are insulated by an insulator 2FIa andthe conductors 2Fb and 2Fc are insulated and separated by an insulator2FIb. Furthermore, the circuit is so configured that the respectiveconductors 2Fa, 2Fb, and 2Fc are separately connected to the controlcircuit 101 such that change in self-capacitance can be detected in thecontrol circuit 101 based on a configuration similar to theabove-described configuration.

In this example of FIG. 13C, when a user holds the part of theconductors 2Fc and 2Fb with a hand or fingers, it can be guessed thatthe user is merely holding the transmission-type electronic pen 1E andthe state for carrying out position indication by the transmission-typeelectronic pen 1E has not yet been established, and therefore thecontrol circuit 101 carries out control to set the transmission circuit102 to the state of the power saving mode. Furthermore, when a userholds the part of the conductor 2Fa with a hand or fingers, it can beguessed that the user intends to carry out position indication by thetransmission-type electronic pen, and therefore the control circuit 101carries out control to set the transmission circuit 102 to the normaltransmission operation state.

In the case of the above-described FIGS. 13A to 13C, the transmissioncircuit 102 may be kept stopping transmission instead of setting thetransmission circuit 102 to the power saving mode. Furthermore, in thiscase, when the transmission circuit 102 is in the transmission operationstate, the transmission of the transmission circuit 102 may be stoppedwhen the part of the conductor 2Db, the part of the conductor 2Eb, orthe part of the conductors 2Fc and 2Fb is held.

In the case of the example of FIG. 13A and the case of the example ofFIG. 13C, the following modification example is also possible.Specifically, the transmission-type electronic pen is configured tocarry out not only transmission of a signal SA from the core body 4 ofan electrical conductor but also transmission of a signal SB from thelid side on the opposite side to the core body 4 in the case 2 in theaxial center direction. In this case, the signal SA and the signal SBare given different frequencies, different patterns, or the like so thatboth can be discriminated on the position detecting device side.Furthermore, in the case of this example, not only is the configurationso made as to allow detection of application of a writing pressure tothe core body 4 but the configuration is so made as to allow detectionof application of a writing pressure also regarding the lid side on theopposite side to the core body 4.

Furthermore, in the case of the transmission-type electronic pen of theexample in which the signal SB is also transmitted from the lid side, inthe configuration example of FIG. 13A or FIG. 13C, control is so carriedout so that the signal SA is transmitted from the core body 4 when auser holds the part of the conductor 2Da or 2Fa with a hand or fingersand the signal SB is transmitted from the lid side on the opposite sideto the core body 4 when the user holds the part of the conductor 2Db or2Fc with a hand or fingers. Furthermore, also in this example, in eachof the case in which the user holds the part of the conductor 2Da or 2Fawith a hand or fingers and the case in which the user holds the part ofthe conductor 2Db or 2Fc with a hand or fingers, with reference also tothe detection result of application of a writing pressure, thetransmission operation state about the signal SA or the signal SB iscontrolled to carry out power saving control similar to theabove-described first embodiment and second embodiment.

The conductors 2Da and 2Db of the case 2D, the conductors 2Ea and 2Eb ofthe case 2E, and the conductors 2Fa, 2Fb, and 2Fc of the case 2F are notconnected to but separated from the ground conductor of the printedboard 8.

Seventh Embodiment

The transmission circuit 102 of the transmission-type electronic pens ofthe above-described embodiments internally includes an oscillator.However, the embodiments can be applied also to a transmission-typeelectronic pen including a transmission circuit that transmits a signalwithout internally including an oscillator as in the above-describedembodiments.

FIG. 14 is a diagram showing a configuration example of atransmission-type electronic pen 1G of this example. Thetransmission-type electronic pen 1G of this example has a configurationsimilar to that of an electronic pen disclosed in e.g., a priordocument: Japanese Patent Publication No. 2012-221304.

As shown in FIG. 14, a tubular case 2G of the transmission-typeelectronic pen 1G of this example includes a case main body 21G composedof a conductor and a front cap 22G composed of a conductor. The casemain body 21G and the front cap 22G are insulated by an insulatingmember 2GI. In the tubular case 2G, a control circuit 101G, a signalprocessing circuit 102G, a battery 5G, and a writing pressure detectingmodule 7G are housed. A core body 4G composed of a conductor is arrangedto be fitted to the writing pressure detecting module 7G.

The core body 4G, the writing pressure detecting module 7G, the controlcircuit 101G, and the battery 5G are given the same configurations asthe above-described embodiments. A variable-capacitance capacitor thatforms the writing pressure detecting module 7G is connected to thecontrol circuit 101G as with the above-described embodiments and thecontrol circuit 101G is configured to be capable of detecting thewriting pressure applied to the core body 4G based on change in thecapacitance of this variable-capacitance capacitor.

Furthermore, the case main body 21G is connected to the control circuit101G as with the above-described embodiments and the control circuit101G is configured to detect contact of a hand or finger of a user withthe case main body 21G. As shown in

FIG. 14, one terminal of the battery 5G is connected to the groundconductor of the printed board and this ground conductor is separatedfrom the conductors 21G and 22G.

A position detecting device used with the transmission-type electronicpen 1G of this example transmits a signal to the transmission-typeelectronic pen 1G. The transmission-type electronic pen 1G of thisexample receives a signal sent from the position detecting device andsupplies the received signal to the signal processing circuit 102G. Thesignal processing circuit 102G accentuates the input received signalthrough amplification or the like to generate a transmission signal bythe transmission-type electronic pen 1G. Then, the signal processingcircuit 102G transmits the generated transmission signal to feed it backto the position detecting device.

In this example, a signal from the position detecting device is receivedby the core body 4G and the received signal is supplied to the signalprocessing circuit 102G. The signal processing circuit 102G transmits agenerated transmission signal to the position detecting device throughthe front cap 22G composed of a conductor. The configuration may be madesuch that a signal from the position detecting device is received by thefront cap 22G and the received signal is supplied to the signalprocessing circuit 102G and a signal generated by the signal processingcircuit 102G is fed back to the position detecting device through thecore body 4G.

Therefore, the signal processing circuit 102G forms a transmissioncircuit in the transmission-type electronic pen 1G and accentuates areceived signal through amplification or the like as the transmissionoperation state. The control circuit 101G is configured to controlactivation and the transmission operation state of this signalprocessing circuit 102G.

Furthermore, in the transmission-type electronic pen 1G of this example,the control circuit 101G controls activation and the transmissionoperation state of the signal processing circuit 102G to carry out powersaving control similarly to the above-described embodiments based on adetection result of contact of a hand or finger of a user with the casemain body 21G and a detection result of the writing pressure applied tothe core body 4G based on change in the capacitance of thevariable-capacitance capacitor of the writing pressure detecting module7.

In the case of this example, the normal transmission operation state inthe signal processing circuit 102G is the state in which a signalobtained by accentuating a received signal through amplification toallow the position detecting device to sufficiently detect an indicatedposition is generated. Furthermore, the transmission operation state ofthe power saving mode of the signal processing circuit 102G is the statein which the hover state of the transmission-type electronic pen 1G canbe detected in the position detecting device but the amplitude of thegenerated signal is set lower than in the normal transmission operationstate or a signal whose repetition cycle of a predetermined pattern likethe above-described one is set longer than in the normal transmissionoperation state is generated.

Therefore, the same effects as the above-described embodiments areachieved also in the transmission-type electronic pen 1G of this fourthembodiment.

[Other Embodiments/Modification Examples]

In the second embodiment, the third embodiment, and the fourthembodiment, the power saving mode may be set at not one stage butmultiple stages. Furthermore, in the second embodiment, the thirdembodiment, and the fourth embodiment, a transition may be made directlyto the sleep mode without going through the power saving mode when apredetermined time elapses without detection of a writing pressure inthe normal operation mode.

Moreover, the method for detecting the state in which a hand or fingerof a human body is in contact with the case main body 21 or the frontcap 22 in the circuit configuration shown in FIG. 5 is none limitingexample. A configuration is also possible in which the case main body 21and the front cap 22 are connected to a specific terminal of an IC thatforms the control circuit 101 and one capacitance for integration isexternally arranged. In addition, the capacitive touch detection methodfor detecting the state in which a hand or finger of a human body is incontact with the case main body 21 or the front cap 22 may be either aself-induction system (self capacitance) or a mutual induction system(mutual capacitance).

Furthermore, in the above-described embodiments, the writing pressuredetector is an example of pressure sensor. The variable-capacitancecapacitor in which a dielectric is sandwiched by a first electrode and asecond electrode is used and the capacitance is allowed to varyaccording to the writing pressure by permitting one of the firstelectrode and the second electrode to move in the axial center directionaccording to the writing pressure. However, the writing pressuredetector is not limited to this configuration. For example, it is alsopossible to form the writing pressure detector by using a semiconductorelement that allows capacitance to vary according to the writingpressure like one disclosed in Japanese Patent Publication No.2013-161307. Furthermore, the writing pressure detector may be formed byusing a structure or element that allows not capacitance but aninductance value or resistance value to vary according to the writingpressure.

Furthermore, in the above-described embodiments, the writing pressuredetector that can continuously measure the writing pressure value isused as the pressure sensor. However, a switch (tact switch) that isturned on according to the pressure applied to the core body may be usedinstead of the writing pressure detector and detection of whether theswitch is turned on may be made. Moreover, as the pressure sensor, apressure sensing resistor sensor that generates a resistance valueaccording to the pressure applied to the core body may be used insteadof the switch. Alternatively, an optical sensor that includes a lightemitting element and a light receiving element may be used. The opticalsensor has a configuration in which the amount of light reception in thelight receiving element is changed according to the pressure applied tothe core body.

The case in which the transmission-type electronic pen of theabove-described embodiment is an electronic pen of the capacitive systemused with a position detecting device of the capacitive system isemployed. However, the transmission-type electronic pen of theabove-described embodiment can be similarly applied also to the case ofa transmission-type electronic pen of the electromagnetic inductionsystem.

Furthermore, a transmission-type electronic pen of a type internallyincluding a primary battery is employed as the transmission-typeelectronic pens of the above-described embodiments. However, atransmission-type electronic pen of a charge system may be used thatinternally includes a secondary battery or internally includes anelectric double-layer capacitor and charges them by a charge device, ofcourse.

DESCRIPTION OF REFERENCE SYMBOLS

1, 1A, 1B, 1C, 1D, 1E, 1F, 1G Transmission-type electronic pen,

2 Case (casing),

4 Core body,

5 Battery,

6 Core body holder,

7 Writing pressure detecting module,

8 Printed board,

21 Case main body,

22 Front cap,

101 Control circuit,

102 Transmission circuit, and

102G Signal processing circuit

The various embodiments described above can be combined to providefurther embodiments. All of the U.S. patents, U.S. patent applicationpublications, U.S. patent applications, foreign patents, foreign patentapplications and non-patent publications referred to in thisspecification and/or listed in the Application Data Sheet areincorporated herein by reference, in their entirety. Aspects of theembodiments can be modified, if necessary to employ concepts of thevarious patents, applications and publications to provide yet furtherembodiments.

These and other changes can be made to the embodiments in light of theabove-detailed description. In general, in the following claims, theterms used should not be construed to limit the claims to the specificembodiments disclosed in the specification and the claims, but should beconstrued to include all possible embodiments along with the full scopeof equivalents to which such claims are entitled. Accordingly, theclaims are not limited by the disclosure.

The invention claimed is:
 1. A transmission-type electronic pen usedwith a position detecting device, the transmission-type electronic pencomprising: a tubular casing; a core body arranged in the casing suchthat a tip of the core body protrudes to extend from one opening of thecasing; a conductor placed near the one opening of the casing; apressure detection circuit configured to detect whether a pressure isapplied to the tip of the core body; and a signal transmission circuit;a signal processing circuit configured to control, in cooperation withthe signal transmission circuit, electrostatic transmission of aposition indicating signal, via the conductor, to the position detectingdevice; and a contact detection circuit configured to detect whether auser's body is in contact with the casing; wherein, the signalprocessing circuit is operable in different operation modes including afirst operation mode, in which the position indicating signal is nottransmitted via the conductor, a second operation mode, in which theposition indicating signal is transmitted via the conductor, and a thirdoperation mode, in which the position indicating signal is transmittedvia the conductor wherein a repetition cycle of the position indicatingsignal transmitted to the position detecting device is longer in thethird operation mode than in the second operation mode, the signalprocessing circuit is operable, in response to the contact detectioncircuit detecting a user body contact with the casing, to transitionfrom the first operation mode to the second operation mode or to thethird operation mode, and the signal processing circuit is operable, inresponse to the pressure detection circuit not detecting a definedpressure within a defined time period after transitioning to the secondoperation mode, to transition back from the second operation mode to thefirst operation mode.
 2. The transmission-type electronic pen accordingto claim 1, wherein: the signal processing circuit is operable, inresponse to the pressure detection circuit detecting a defined pressureafter transitioning to the third operation mode, to transition from thethird operation mode to the second operation mode.
 3. Thetransmission-type electronic pen according to claim 2, wherein: anamplitude of the position indicating signal is lower in the thirdoperation mode than in the second operation mode.
 4. Thetransmission-type electronic pen according to claim 1, wherein thecontact detection circuit is configured to detect whether a user's handis in contact with the casing.
 5. The transmission-type electronic penaccording to claim 1, wherein the conductor forms the core body.
 6. Atransmission-type electronic pen used with a position detecting device,the transmission-type electronic pen comprising: a tubular casing; acore body arranged in the casing such that a tip of the core bodyprotrudes to extend from one opening of the casing; a conductor placednear the one opening of the casing; a pressure detection circuitconfigured to detect whether a pressure is applied to the tip of thecore body; and a signal transmission circuit; a signal processingcircuit configured to control, in cooperation with the signaltransmission circuit, electrostatic transmission of a positionindicating signal, via the conductor, to the position detecting device;and a motion sensor circuit configured to detect a motion of the casing;wherein, the signal processing circuit is operable in differentoperation modes including a first operation mode, in which the positionindicating signal is not transmitted via the conductor, a secondoperation mode, in which the position indicating signal is transmittedvia the conductor, and a third operation mode, in which the positionindicating signal is transmitted via the conductor wherein a repetitioncycle of the position indicating signal transmitted to the positiondetecting device is longer in the third operation mode than in thesecond operation mode, the signal processing circuit is operable, inresponse to the motion sensor circuit detecting a motion of the casing,to transition from the first operation mode to the second operation modeor to the third operation mode, and the signal processing circuit isoperable, in response to the pressure detection circuit not detecting adefined pressure within a defined time period after transitioning to thesecond operation mode, to transition back from the second operation modeto the first operation mode.
 7. The transmission-type electronic penaccording to claim 6, wherein: the signal processing circuit isoperable, in response to the pressure detection circuit detecting adefined pressure after transitioning to the third operation mode, totransition from the third operation mode to the second operation mode.8. The transmission-type electronic pen according to claim 7, wherein:an amplitude of the position indicating signal is lower in the thirdoperation mode than in the second operation mode.
 9. A transmission-typeelectronic pen used with a position detecting device, thetransmission-type electronic pen comprising: a tubular casing; a corebody arranged in the casing such that a tip of the core body protrudesto extend from one opening of the casing; a conductor placed near theone opening of the casing; a pressure detection circuit configured todetect whether a pressure is applied to the tip of the core body; and asignal transmission circuit; a signal processing circuit configured tocontrol, in cooperation with the signal transmission circuit,electrostatic transmission of a position indicating signal, via theconductor, to the position detecting device; and a contact detectioncircuit configured to detect whether a user's body is in contact withthe casing; wherein, the signal processing circuit is operable indifferent operation modes including a first operation mode, in which theposition indicating signal is not transmitted via the conductor, asecond operation mode, in which the position indicating signal istransmitted via the conductor, and a third operation mode, in which theposition indicating signal is transmitted via the conductor wherein arepetition cycle of the position indicating signal transmitted to theposition detecting device is longer in the third operation mode than inthe second operation mode, the signal processing circuit is operable, inresponse to the contact detection circuit detecting a user body contactwith the casing and the pressure detection circuit detecting a definedpressure, to enter into the second operation mode, and the signalprocessing circuit is operable, in response to the pressure detectioncircuit not detecting a defined pressure, to transition from the secondoperation mode to the first operation mode upon expiration of a secondtime period after entering into the second operation mode.
 10. Thetransmission-type electronic pen according to claim 9, wherein: thesignal processing circuit is operable to transition from the thirdoperation mode to the first operation mode upon expiration of a thirdtime period after transitioning to the third operation mode.
 11. Thetransmission-type electronic pen according to claim 10, wherein: anamplitude of the position indicating signal is lower in the thirdoperation mode than in the second operation mode.
 12. Thetransmission-type electronic pen according to claim 9, wherein thecontact detection circuit is configured to detect whether a user's handis in contact with the casing.
 13. A transmission-type electronic penused with a position detecting device, the transmission-type electronicpen comprising: a tubular casing; a core body arranged in the casingsuch that a tip of the core body protrudes to extend from one opening ofthe casing; a conductor placed near the one opening of the casing; apressure detection circuit configured to detect whether a pressure isapplied to the tip of the core body; and a signal transmission circuit;a signal processing circuit configured to control, in cooperation withthe signal transmission circuit, electrostatic transmission of aposition indicating signal, via the conductor, to the position detectingdevice; and a motion sensor circuit configured to detect a motion of thecasing; wherein, the signal processing circuit is operable in differentoperation modes including a first operation mode, in which the positionindicating signal is not transmitted via the conductor, a secondoperation mode, in which the position indicating signal is transmittedvia the conductor, and a third operation mode, in which the positionindicating signal is transmitted via the conductor wherein a repetitioncycle of the position indicating signal transmitted to the positiondetecting device is longer in the third operation mode than in thesecond operation mode, the signal processing circuit is operable, inresponse to the motion sensor circuit detecting a motion of the casingand the pressure detection circuit detecting a defined pressure, toenter into the second operation mode, and the signal processing circuitis operable, in response to the pressure detection circuit not detectinga defined pressure, to transition from the second operation mode to thefirst operation mode upon expiration of a second time period afterentering into the second operation mode.
 14. The transmission-typeelectronic pen according to claim 13, wherein: the signal processingcircuit is operable to transition from the third operation mode to thefirst operation mode upon expiration of a third time period aftertransitioning to the third operation mode.
 15. The transmission-typeelectronic pen according to claim 14, wherein: an amplitude of theposition indicating signal is lower in the third operation mode than inthe second operation mode.
 16. A transmission-type electronic pen usedwith a position detecting device, the transmission-type electronic pencomprising: a tubular casing; a core body arranged in the casing suchthat a tip of the core body protrudes to extend from one opening of thecasing; a first conductor and a second conductor placed near the oneopening of the casing; a pressure detection circuit configured to detectwhether a pressure is applied to the tip of the core body; and a signaltransmission circuit; a signal reception circuit configured to receive adetector signal transmitted from the position detecting device via thesecond conductor; a signal processing circuit configured to control, inresponse to the detector signal and in cooperation with the signaltransmission circuit, electrostatic transmission of a positionindicating signal, via the first conductor, to the position detectingdevice; and a contact detection circuit configured to detect whether auser's body is in contact with the casing; wherein, the signalprocessing circuit is operable in different operation modes including afirst operation mode, in which the position indicating signal is nottransmitted via the first conductor, a second operation mode, in whichthe position indicating signal is transmitted via the first conductorconductor and a third operation mode, in which the Position indicatingsignal is transmitted via the first conductor wherein a repetition cycleof the position indicating signal transmitted to the position detectingdevice is longer in the third operation mode than in the secondoperation mode, the signal processing circuit is operable, in responseto the contact detection circuit detecting a user body contact with thecasing, to transition from the first operation mode to the secondoperation mode, and the signal processing circuit is operable, inresponse to the pressure detection circuit not detecting a definedpressure within a defined time period after transitioning to the secondoperation mode, to transition back from the second operation mode to thefirst operation mode.
 17. The transmission-type electronic pen accordingto claim 16, wherein: the signal processing circuit is operable, inresponse to the pressure detection circuit detecting a defined pressureafter transitioning to the third operation mode, to transition from thethird operation mode to the second operation mode.
 18. Thetransmission-type electronic pen according to claim 17, wherein: anamplitude of the position indicating signal is lower in the thirdoperation mode than in the second operation mode.
 19. Thetransmission-type electronic pen according to claim 16, wherein thecontact detection circuit is configured to detect whether a user's handis in contact with the casing.
 20. The transmission-type electronic penaccording to claim 16, wherein the first conductor forms the core body.21. The transmission-type electronic pen according to claim 16, whereinthe signal reception circuit is configured to receive a signal from theposition detecting device via the second conductor.
 22. Atransmission-type electronic pen used with a position detecting device,the transmission-type electronic pen comprising: a tubular casing; acore body arranged in the casing such that a tip of the core bodyprotrudes to extend from one opening of the casing; a first conductorand a second conductor placed near the one opening of the casing; apressure detection circuit configured to detect whether a pressure isapplied to the tip of the core body; and a signal transmission circuit;a signal reception circuit configured to receive a detector signaltransmitted from the position detecting device via the second conductor;a signal processing circuit configured to control, in response to thedetector signal, and in cooperation with the signal transmissioncircuit, electrostatic transmission of a position indicating signal, viathe first conductor, to the position detecting device; and a motionsensor circuit configured to detect a motion of the casing; wherein, thesignal processing circuit is operable in different operation modesincluding a first operation mode, in which the position indicatingsignal is not transmitted via the first conductor, a second operationmode, in which the position indicating signal is transmitted via thefirst conductor, and a third operation mode, in which the positionindicating signal is transmitted via the first conductor wherein arepetition cycle of the position indicating signal transmitted to theposition detecting device is longer in the third operation mode than inthe second operation mode, the signal processing circuit is operable, inresponse to the motion sensor circuit detecting a motion of the casing,to transition from the first operation mode to the second operationmode, and the signal processing circuit is operable, in response to thepressure detection circuit not detecting a defined pressure within adefined time period after transitioning to the second operation mode, totransition back from the second operation mode to the first operationmode.
 23. The transmission-type electronic pen according to claim 22,wherein: the signal processing circuit is operable, in response to thepressure detection circuit detecting a defined pressure aftertransitioning to the third operation mode, to transition from the thirdoperation mode to the second operation mode.
 24. The transmission-typeelectronic pen according to claim 23, wherein: an amplitude of theposition indicating signal is lower in the third operation mode than inthe second operation mode.
 25. The transmission-type electronic penaccording to claim 22, wherein the first conductor forms the core body.26. The transmission-type electronic pen according to claim 22, whereinthe signal reception circuit is configured to receive a signal from theposition detecting device via the second conductor.